Although a number of devices and mechanisms are available for use in the dissipation of heat generated by electronic and mechanical devices, one of the most effective is a simple fan. The fan is generally positioned on or near the device in a manner that will dissipate heat generated by the device into the surrounding ambient air. In recent years, electronic devices have become more and more compact, which means that fans being used for the transfer of heat away from the device circuitry have also become very small. On the other hand, other mechanical or electronic devices may be very large, requiring large fans for heat control. In some cases a cooling fan will be dedicated to the removal of heat from a single device or circuit, while at other times a fan, or fans, will be used to remove heat generated by a plurality of devices circuits. In each of the foregoing cases, a fan failure may be critical.
Because heat is one of the primary causes of electrical component failure, if a cooling fan fails there is a substantial risk that a component in a device will fail or, at the very least, the device's useful life will be shortened considerably. Of course, if a component fails, the entire device is also at risk of failure. Thus, an apparatus, mechanism or device to predict fan wear-out and impending failure is important from a maintenance point of view.
At present the most prevalent practice in dealing with a fan failure is to do nothing until the fan actually fails or it is readily apparent that the fan will shortly fail, such as where the fan starts emitting a grinding or squealing sound. At least one prior art method exists to predict fan wear out and impending fan failure. This prior art method uses current sensing or voltage sensing circuitry to measure fan input energy and then compares the sensed energy input with a predetermined energy input requirement for a given fan at a given fan speed. The disadvantage of this prior art method is that it requires additional hardware, at an additional cost. The additional hardware required is a power measurement circuit to measure current or voltage input to determine the fan input energy.
Accordingly, what is needed in the art is an apparatus and method to determine fan wear-out and impending fan failure that does not require additional hardware.